My present invention relates to a mechanism of operation of a rechargeable electrically powered tool, particularly a hair cutting device having a rechargeable battery, which can be powered either by line voltage or the battery.
To allow unrestricted mobility a hair cutting device with a built in rechargeable battery is used preponderantly in hair dressing which, when not in use, is inserted in a holder which simultaneously acts as a charging device. Furthermore spring-like contacts, on which the device being charged presses of its own weight, are provided in the holder. Current or power is supplied to the spring-like contacts from a power supply unit which is integrated in a line-powered power supply plug, so that the battery is subsequently charged.
Because of ergonomic considerations a hair cutting device should be both small and light which, of course, provides negative constraints on the life of the battery charge. It is especially important that on discharge of the battery during hair cutting the hairdresser has the option to continue to operate the unit.